GRAVEL HARDER. ADVENTURE FURTHER. The Helix Race 107 BCD Chainring is a high-value quality upgrade for Gravel and Road Cyclists using 4-bolt 107 BCD cranks such as SRAM® XPLR or Power Meter Cranks like Quarq Force or Rival. Take full advantage of e*thirteen’s widest range cassettes by dropping 2 teeth or more in chainring size with our smaller 38, 40, and 42T sizes. A combo that supports steeper climbs and faster descents. Helix Race 107 BCD rings are forged from long-wearing 7075 alloy and CNC optimized for stiffness, lightweight, and chain-retaining performance. Black & grey color options to coordinate with e*thirteen 9-45T and 9-50T cassettes. Like all e*thirteen chainrings, they feature cross-compatible tooth profiles, switching seamlessly between SRAM® or Shimano® 11 and 12-speed drivetrains for absolute build freedom. Chainline is determined by SRAM® crank assembly, 45mm for normal width cranks, 47.5mm for wide cranks. SRAM® is a Registered Trademark of SRAM LLC.